This invention relates to catalytic reactions. In one of its aspects this invention relates to the introduction of catalyst into a reactor. In another of its aspects it relates to a method and apparatus for introducing measured quantities of catalyst slurry into a reactor with positive shut-off of catalyst flow between deliveries of measured quantities of catalyst. In another of its aspects this invention relates to the automatic transfer of catalyst to a reactor with delivery of measured quantities without leakage of catalyst to the reactor between regulated catalyst dosages.
In many chemical reactions, particularly in the polymerization of certain hydrocarbon monomers, a catalyst is utilized to promote the chemical reaction. It is well known that most reactions are sensitive to the quantity of catalyst utilized so that the production rate of the reaction can be controlled by controlling the rate of catalyst feed to the reaction. Accordingly, method and apparatus have been devised for accurate rate of feeding catalyst to a reaction and for provision of positive catalyst feed shut-off to the reaction.
One method for assuring accurate catalyst dosages to a reaction is the use of a double-check ball feeder valve which provides for inlet of a measured amount of catalyst into a ball valve chamber with subsequent rotation of the chamber from inlet to outlet position thereby releasing the measured amount of catalyst to the reactor system. Most reaction systems utilizing this type of valve also provide flush of carrier material for the catalyst downstream of the measuring device to assure positive transfer of the catalyst from the ball valve to the reaction system. One of the problems encountered with a double-check ball feed valve system is the leakage of the feed valve under shut-off conditions so that amounts of unwanted catalyst find a way through the feed system into the reaction system thereby increasing the reaction rate.
It is therefore an object of this invention to provide a method and apparatus for preventing a reaction in a chemical reactor from being affected by leakage of catalyst past a ball check catalyst feed valve. It is another object of this invention to provide apparatus and method for automatically delivering a controlled amount of catalyst feed to reaction system. It is still another object of this invention to provide apparatus and method for positive shut-off of catalyst flow between periods of delivering a needed amount of catalyst into a reaction system.
Other aspects, objects and the various advantages of this invention will become apparent upon study of the specifications, drawings and appended claims.